1. Perron, O., Die Stabilitӓtsfrage bei Differentialgleichungen, Math. Z., 1930, vol. 32, no. 5, pp. 703–728.
2. Hadamard, J., Sur l’itération et les solutions asymptotiques des équations différentielles, Bull. Soc. Math. France, 1901, vol. 29, pp. 224–228.
3. Bohl, P., Über Differentialungleichungen, J. Reine Angew. Math., 1913, vol. 144, no. 4, pp. 284–318.
4. Maizel’, A.D., On the stability of solutions of systems of differential equations, Tr. Ural. Politekh. Inst. Ser. Mat., 1954, vol. 51, pp. 20–50.
5. Massera, J.L. and Schӓffer, J.J., Linear differential equations and functional analysis, I, Ann. Math., 1958, vol. 67, no. 3, pp. 517–573.